Gérard Savary

Dietary sodium butyrate supplementation increases digestibility and pancreatic secretion in young milk-fed calves

The aim of this study was to test, in 8 calves fed milk formula based on soybean protein, the ability of sodium butyrate (SB) supplementation to improve nutrient digestibility and daily pancreatic secretions and to modify the kinetics of these secretions. Additionally, effects of duodenal SB infusion were evaluated. Plasma levels of gastrin, secretin, and cholecystokinin were measured. Butyrate supplementation in milk formula increased nutrient digestibility and total daily pancreatic secretions. For juice volume, this increase was most important from 12 to 17h after the morning meal. During the 3-h postprandial period, oral SB supplementation reduced the physiological decrease of postprandial pancreatic secretion (while duodenal digesta flow rate was maximal) and had a minor effect on plasma gut regulatory peptide concentrations. Compared with the diet without SB, ingestion of SB stimulated pancreatic secretion. Taken together, these results could explain the measured increase in nutrient digestibility. The data obtained after duodenal SB infusion did not indicate an effect on pancreatic secretion, apart from elevated lipase output compared with control. The mechanisms responsible for these events are not known and circulating gut regulatory peptides do not seem to be implicated. Our work brings new results regarding SB as a feed additive in young calf nutrition.

Maternal short-chain fructooligosaccharide supplementation influences intestinal immune system maturation in piglets.

Peripartum nutrition is crucial for developing the immune system of neonates. We hypothesized that maternal short-chain fructooligosaccharide (scFOS) supplementation could accelerate the development of intestinal immunity in offspring. Thirty-four sows received a standard or a scFOS supplemented diet (10 g scFOS/d) for the last 4 weeks of gestation and the 4 weeks of lactation. Colostrum and milk immunoglobulins (Ig) and TGFβ1 concentrations were evaluated on the day of delivery and at d 6 and d 21 postpartum. Piglet intestinal structure, the immunologic features of jejunal and ileal Peyers patches, and mesenteric lymph node cells were analysed at postnatal d 21. Short-chain fatty acid concentrations were measured over time in the intestinal contents of suckling and weaned piglets. Colostral IgA (P<0.05) significantly increased because of scFOS and TGFβ1 concentrations tended to improve (P<0.1). IFNγ secretion by stimulated Peyers patch and mesenteric lymph node cells, and secretory IgA production by unstimulated Peyers patch cells were increased (P<0.05) in postnatal d 21 scFOS piglets. These differences were associated with a higher proportion of activated CD25+CD4α+ T cells among the CD4+ helper T lymphocytes (P<0.05) as assessed by flow cytometry. IFNγ secretion was positively correlated with the population of activated T lymphocytes (P<0.05). Total short-chain fatty acids were unchanged between groups during lactation but were higher in caecal contents of d 90 scFOS piglets (P<0.05); specifically propionate, butyrate and valerate. In conclusion, we demonstrated that maternal scFOS supplementation modified the intestinal immune functions in piglets in association with increased colostral immunity. Such results underline the key role of maternal nutrition in supporting the postnatal development of mucosal immunity.

A high-protein formula increases colonic peptide transporter 1 activity during neonatal life in low-birth-weight piglets and disturbs barrier function later in life.

Dietary peptides are absorbed along the intestine through peptide transporter 1 (PepT-1) which is highly responsive to dietary protein level. PepT-1 is also involved in gut homeostasis, both initiating and resolving inflammation. Low-birth-weight (LBW) neonates are routinely fed a high-protein (HP) formula to enhance growth. However, the influence of this nutritional practice on PepT-1 activity is unknown. Intestinal PepT-1 activity was compared in normal-birth-weight (NBW) and LBW piglets. The effect of HP v. normal-protein (NP) formula feeding on PepT-1 activity and gut homeostasis in LBW piglets was evaluated, during the neonatal period and in adulthood. Flux of cephalexin (CFX) across the tissue mounted in Ussing chambers was used as an indicator of PepT-1 activity. CFX flux was greater in the ileum, but not jejunum or colon, of LBW than NBW piglets during the neonatal period. When LBW piglets were formula-fed, the HP formula increased colonic CFX during the 1st week of life. Later in life, intestinal CFX fluxes and barrier function were similar whether LBW pigs had been fed NP or HP formula. However, colonic permeability of HP- but not NP-fed pigs increased when luminal pH was brought to 6·0. The formyl peptide N-formyl methionyl-leucyl-phenylalanine conferred colonic barrier protection in HP-fed piglets. Heat shock protein 27 levels in the colonic mucosa of HP-fed LBW pigs correlated with the magnitude of response to the acidic challenge. In conclusion, feeding a HP formula enhanced colonic PepT-1 activity in LBW pig neonates and increased sensitivity of the colon to luminal stress in adulthood.

Maternal 18:3n-3 favors piglet intestinal passage of LPS and promotes intestinal anti-inflammatory response to this bacterial ligand.

We recently observed that maternal 18:3n-3 increases piglet jejunal permeability. We hypothesized that this would favor intestinal lipopolysaccharide (LPS) passage and alter gut immune system education toward this bacterial ligand. Sows were fed 18:3n-3 or 18:2n-6 diets throughout gestation and lactation. In each litter, two piglets were given oral Gram-negative spectrum antibiotic from post-natal day (PND) 14 to 28. All piglets were weaned on a regular diet at PND28. 18:3n-3 piglets exhibited greater jejunal permeability to FITC-LPS at PND28. Levels of 18:3n-3 but neither 20:5n-3 nor 20:4n-6 were greater in mesenteric lymph nodes (MLN) of 18:3n-3 piglets. Jejunal explant or MLN cell cytokine responses to LPS were not influenced by the maternal diet. Antibiotic increased jejunal permeability to FITC-LPS and lowered the level of 20:5n-3 in MLN, irrespective of the maternal diet. At PND52, no long-lasting effect of the maternal diet or antibiotic treatment on jejunal permeability was noticed. 18:3n-3 and 20:4n-6 levels were greater and lower, respectively, in MLN of 18:3n-3 compared to 18:2n-6 piglets. IL-10 production by MLN cells in response to LPS was greater in the 18:3n-3 group, irrespective of the neonatal antibiotic treatment. IL-8 secretion by jejunal explants in response to LPS was lower in antibiotic-treated 18:3n-3 compared to 18:2n-6 piglets. Finally, proportion of MHC class II(+) antigen-presenting cells was greater in 18:3n-3 than 18:2n-6 MLN cells. In conclusion, maternal 18:3n-3 directs the intestinal immune response to LPS toward an anti-inflammatory profile beyond the breastfeeding period; microbiota involvement seems dependent of the immune cells considered.

Is there adaptation of the exocrine pancreas in wild animal? The case of the Roe Deer

BackgroundPhysiology of the exocrine pancreas has been well studied in domestic and in laboratory animals as well as in humans. However, it remains quite unknown in wildlife mammals. Roe deer and cattle (including calf) belong to different families but have a common ancestor. This work aimed to evaluate in the Roe deer, the adaptation to diet of the exocrine pancreatic functions and regulations related to animal evolution and domestication.ResultsForty bovine were distributed into 2 groups of animals either fed exclusively with a milk formula (monogastric) or fed a dry feed which allowed for rumen function to develop, they were slaughtered at 150 days of age. The 35 Roe deer were wild animals living in the temperate broadleaf and mixed forests, shot during the hunting season and classified in two groups adult and young. Immediately after death, the pancreas was removed for tissue sample collection and then analyzed. When expressed in relation to body weight, pancreas, pancreatic protein weights and enzyme activities measured were higher in Roe deer than in calf. The 1st original feature is that in Roe deer, the very high content in pancreatic enzymes seems to be related to specific digestive products observed (proline-rich proteins largely secreted in saliva) which bind tannins, reducing their deleterious effects on protein digestion. The high chymotrypsin and elastase II quantities could allow recycling of proline-rich proteins. In contrast, domestication and rearing cattle resulted in simplified diet with well digestible components. The 2nd feature is that in wild animal, both receptor subtypes of the CCK/gastrin family peptides were present in the pancreas as in calf, although CCK-2 receptor subtype was previously identified in higher mammals.ConclusionsBovine species could have lost some digestive capabilities (no ingestion of great amounts of tannin-rich plants, capabilities to secrete high amounts of proline-rich proteins) compared with Roe deer species. CCK and gastrin could play an important role in the regulation of pancreatic secretion in Roe deer as in calf. This work, to the best of our knowledge is the first study which compared the Roe deer adaptation to diet with a domesticated animal largely studied.

Pancreatic enzyme deficiency depends on dietary protein origin in milk-fed calves

In young mammals, milk proteins and their substitutes are used in milk formula. Protein substitution modifies diet digestibility and pancreatic secretions. The aim of this study was to test if milk protein substitution could generate pancreatic deficiency in milk-fed calves. The effect of pancreatic juice on the digestibility of proteins was studied. Measurement of apparent fecal nutrient digestibility was used to estimate digestion. Ten calves (60 to 130 d old) were chronically fitted with pancreatic accessory duct cannulas and 2 duodenal cannulas to provide precise measurement, sampling, and reintroduction of pancreatic juice as well as additional infusions. Animals were fed milk formula based on skim milk powder or soybean concentrate. Level of deficiency depended on dietary protein origin. Twice as much protein or trypsin was required with a soybean concentrate diet than with a skim milk powder diet to obtain maximal nutrient digestibility. Pancreatic protein concentration in the juice can be used to differentiate between normal and deficient animals. Among these proteins, trypsin measurement is a good pancreatic deficiency marker. These results confirmed the major role of exocrine pancreatic secretions in producing optimal digestion in young calves. Furthermore, practical applications of these results can be applied for the young in other animal species and in humans.

Defatted bovine colostrum-supplemented diet around weaning improves exocrine pancreatic secretion by means of volume, digestive enzymes, and antibacterial activity.

Objectives: Exocrine pancreatic secretion contributes to limit pathogenic bacteria-associated diarrhea. Bovine colostrum, used in the treatment of diarrhea, reduces symptoms originating from gut pathogenic bacteria overgrowth. We hypothesized that bovine colostrum may stimulate the exocrine pancreatic secretion. Methods: Eighteen piglets fitted with 2 permanent catheters (for pancreatic juice collection and reintroduction) were allocated to 1 of the following 2 dietary treatments for 5 days: a control diet or a diet supplemented with defatted bovine colostrum. Pancreatic juice was collected daily, and digestive enzyme activities and antibacterial activity were determined. Results: The prandial pancreatic juice outflow, the basal and prandial lipase output, and the basal secretion of the antibacterial activity were, respectively, 60% (P = 0.08), 154% (P = 0.08), 92% (P = 0.06), and 72% (P < 0.05) higher in piglets fed a diet supplemented with defatted bovine colostrum. Conclusions: With defatted bovine colostrum, the increased antibacterial activity secretion against Escherichia coli may limit pathogenic bacteria overgrowth of the gut and reduce diarrheal episodes. The role of secretin in the increased pancreatic juice flow and lipase secretion was considered.